Everything you need to know about solar: The technology behind it

You are considering putting solar panels on your home to produce electricity, but how does it work, and is your property right for solar panels?

How it works

A solar photovoltaic (PV) system is designed to turn UV light into electricity. The panels that are mounted to your roof are made up of a collection of cells that are formed from several thin layers of semi-conducting silicone that contain metal contacts that absorb UV light.
When UV light is absorbed it enables the electrons within the cells to move around and this movement generates electricity. The electricity generated by the panels is in DC (direct current) but the electrical grid and appliances in your home operate on AC (alternating current). To make the electricity generated compatible, the current is fed through an inverter which changes it into AC.

All solar PV systems also include a meter that allows you to track the amount of energy generated, used and exported to the grid. It is also connected to your consumer unit to allow the electricity to be exported.

Energy storage

The electricity generated by your solar panels will be produced during the day and unless you have a higher than average daytime consumption it is likely that a high proportion of the electricity will be exported to the grid.

Currently there are neither adequate nor cost-effective energy storage solutions for homeowners but advancements in this area have made the likelihood of this happening in the next decade much higher. So, whilst you won’t be able to initially store electricity for your own use, it is likely that during the lifetime of your system it could be possible to add storage to it.

UK conditions for solar PV

Although the UK doesn’t have the hottest of climates, this doesn’t massively reduce the appeal of solar panels, as the UK does have a significant number of daytime hours and UV exposure. The sun doesn’t necessarily need to be out in order for the panels to generate electricity, it is UV light that they require. However, the intensity of the light will impact on the amount of power produced. It is worth carefully accessing what level of electricity the system can generate before purchasing it.

Maximising electricity generated

The location, roof pitch, and shading in relation to the sun’s position throughout the day can greatly alter the amount of electricity generated. A technical survey would take into account these factors combined with the amount of light expected where you live and give an accurate picture of what the system could generate.

Financials

But don’t forget that it’s not just the electricity used that you save money on but that you also get a Feed-in-Tariff (FIT) for all electricity generated and an additional payment for electricity exported to the grid. In the current FIT scheme requirements the level of your Energy Performance Certificate (EPC) rating impacts on the amount of generation tariff you receive so it’s worth improving the energy efficiency of your home first.